In this images of infrared radiation in the days before the March 11 earthquake, the red circle indicates the epicenter and the red lines are tectonic faults.
What’s the News: Scientists analyzing the March 11 earthquake in Japan will have the benefit of some of the most sensitive and comprehensive atmospheric data yet, thanks to satellites monitoring climate. And a team has now reported a strange effect—a sudden spike in the temperature in the atmosphere above the quake site—detected just before the event. If the spike was related to the quake, and other earthquakes do the same thing, it might help scientists predict such cataclysms in the future.
A house decimated by the 2010 earthquake in Chile.
What’s the News: Enormous earthquakes are rare; there have been only seven quakes with a magnitude 8.8 or above since the start of the 20th century. Of those seven quakes, three of them have happened in the past seven years: off the coasts of Indonesia in 2004, Chile in 2010, and Japan last month. Some researchers think this earthquake cluster marks the start of a period of megaquakes, while others believe that the earthquake cluster is simply a statistical fluke, with these unusually massive quakes just happening to occur within a short amount of time, according to recent analyses (PDF) of Earth’s earthquake history presented at the Seismological Society of America’s annual meeting last week.
Reactor 3 at the Fukushima Daiichi plant, on March 24
What’s the News: A non-peer-reviewed study (pdf) publicized last week by radioactivity-detection expert Ferenc Dalnoki-Veress suggests that nuclear fission reactions continued at Japan’s Fukushima nuclear power station well after the plant’s operators had allegedly shut down the reactors there. The paper says there may be what are called “localized criticalities” have occurred in the plutonium and uranium left in the reactors—little pockets of fuel that have gone critical, propagating the nuclear chain reaction and generating potentially harmful radiation. The existence of criticalities is controversial: some researchers say there are certainly none; Dalnoki-Veress himself says it’s only a possibility.
What’s the News: Japan has finally called in the robots to the Fukushima Daiichi nuclear plant, dispatching this red AKA Monirobo that is equipped with radiation detectors, temperature and humidity sensors, and a 3-D camera.
What’s the Olds:
Not So Fast: It isn’t clear how much work (if any) the AKA Monirobo is accomplishing thus far.
Image: Asahi Shimbun
Image: flickr / daveeza
Update (March 15): Shortly after this post was originally published, the situation at the Fukushima Daiichi facility worsened dramatically: there was an explosion at a third reactor, which may have damaged the containment unit there, along with a new fire. Reports elsewhere now suggests that more radioactive material escaped, but the extent of the risk of further release of radioactivity is not yet clear. The title of the post has been edited to reflect the changing situation. (Original title: “Relax: Fears Of Japan’s Radioactive Leakage Are Overblown”)
A second explosion hit Japan’s Fukushima Daiichi nuclear power plant today and authorities are preparing to pump seawater into a third imperiled reactor. But considering that Friday’s earthquake was seven times more powerful than the maximum limit they were designed to withstand, we’re lucky the situation isn’t much worse. Japan’s scenario is a far cry from Chernobyl: Any radioactive leakage that has occurred is low, and unlikely to affect anyone outside the local area (if that).
Both today’s explosion (in reactor No. 3) and the one on Saturday (reactor No. 1) have the same cause: a breakdown in the cooling system as tsunami waters swamped generators. Specifically, today’s explosion was caused by hydrogen gas, which builds up as the seawater that’s pumped in to cool the reactor also heats up. From video footage, the explosion looks devastating, and while 11 people were injured, the steel and concrete containment shell around the nuclear reactor was not damaged—which is the main reason why authorities say the situation is mostly under control. “There is no massive radioactive leakage,” Cabinet Chief Cabinet Secretary Yukio Edano told the New York Times. Here’s a rundown on the risks in the leakage that has occurred:
What Is Escaping (and How)?
The root problem is heat: Even though the nuclear chain reaction is safely stopped in all of Japan’s nuclear reactors, that doesn’t stop heat from building up.
The uranium “stopped” the chain reaction. But a number of intermediate radioactive elements are created by the uranium during its fission process, most notably Cesium and Iodine isotopes, i.e. radioactive versions of these elements that will eventually split up into smaller atoms and not be radioactive anymore. Those elements keep decaying and producing heat. Because they are not regenerated any longer from the uranium (the uranium stopped decaying after the moderator rods were put in), they get less and less, and so the core cools down over a matter of days, until those intermediate radioactive elements are used up. [The Energy Collective]
Oil refineries aflame. Train tracks twisted like string. Buildings ripped from their foundations. Japan’s 8.9-magnitude earthquake has left its mark, especially in the expected death toll of over 1,000 people. This video roundup shows the science behind what happened today in Japan.
Why (Most) Buildings Didn’t Crumble
The death toll is estimated around 1,000, which is bad enough, but it would have been much higher without good engineering, mandated by strict building codes. But these codes haven’t been strict for long. In the 7.3-magnitude Kobe earthquake in 1995, 6,500 Japanese people died, and engineers looked on in horror as many buildings came crashing down; the most deadly ones were built before 1981, when building standards were still lower.
The Kobe tragedy, says The Telegraph‘s Peter Foster, compelled Japanese officials to tighten building regulations for residential offices and transportation infrastructure. Engineers made buildings “earthquake proof” by outfitting them with “deep foundation and massive shock absorbers that dampen seismic energy,” and by enabling the bases of buildings to move “semi-independently to its superstructure, reducing the shaking caused by a quake.” Skyscrapers now sway during an earthquake but don’t collapse, Foster says, and that helps explain why damage to buildings in Tokyo was kept to a minimum this time around. [The Atlantic Wire]
Why Couldn’t Geologists Predict It?
The Internet has been burning up with an ice age storyline over the past few days: Researchers in Japan led by Akira Iritani announced their plan to clone a woolly mammoth within four to six years, recreating a colossal beast not seen on Earth in thousands of years. But as enthusiastic as DISCOVER is for cloned mammoths (and believe us, we’re psyched), the project is still a long way from success.
First, the backstory.
Researchers from Kinki University’s Graduate School of Biology-Oriented Science and Technology began the study in 1997. On three occasions, the team obtained mammoth skin and muscle tissue excavated in good condition from the permafrost in Siberia. However, most nuclei in the cells were damaged by ice crystals and were unusable. The plan to clone a mammoth was abandoned. [Daily Yamiuri]
That initial effort was a DISCOVER cover story back in 1999. Now, though, the dream is back, thanks to newly developed methods to get around that icy problem.
The team, which has invited a Russian mammoth researcher and two US elephant experts to join the project, has established a technique to extract DNA from frozen cells, previously an obstacle to cloning attempts because of the damage cells sustained in the freezing process. Another Japanese researcher, Teruhiko Wakayama of the Riken Centre for Developmental Biology, succeeded in 2008 in cloning a mouse from the cells of another that had been kept in temperatures similar to frozen ground for 16 years. [AFP]